Emergency stopping device for a fuel-injection internal combustion engine

ABSTRACT

In an internal combustion engine of the fuel-injection type fed with fuel by injection pumps, each pump comprising a piston operated by an actuating mechanism releasably connected thereto and with tripping means adapted to slow down and to stop the engine in case of overspeed, at least one servo-motor operated by said tripping means for acting upon said fuel-injection pumps, an emergency stopping arrangement wherein each one of said pumps is provided with an individual servo-motor acting directly upon the piston of said pump to disconnect said piston from its actuating mechanism.

United States atent Kiihn 1 51 Aug. 7, 1973 [541 EMERGENCY STOPPINGDEVICE FOR A 2,719,521 10/1955 King et a1. 123/198 DB FUELJNJECTIQNINTERNAL 2,831,474 4/1958 King et a1. 123/198 DB 2,854,964 10/1958Wagner 123/198 DB COMBUSTION ENGINE 3,388,695 6/1968 O'Donnell 123/198 DInventor:

Assignee:

Filed:

Appl. No.:

Karl Walter Kiihn, Saint-Germain-en-Laye, France Societe DEtudes DeMachines Thermiques, Saint-Denis, France Nov. 22, 1971 ForeignApplication Priority Data Dec. 31, 1970 France 7047558 US. Cl 123/198 DInt. Cl. F02b 77/00 Field of Search 123/198 D, 198 DB References CitedUNITED STATES PATENTS Eppens 123/198 DB Primary E;qmin er-C. J. HusarAttorney-Francis T. Carr and Theodore Ordman [57] ABSTRACT In aninternal combustion engine of the fuel-injection type fed with fuel byinjection pumps, each pump comprising a piston operated by an actuatingmechanism releasably connected thereto and with tripping means adaptedto slow down and to stop the engine in case of overspeed, at least oneservo-motor operated by said tripping means for acting upon saidfuel-injection pumps, an emergency stopping arrangement wherein each oneof said pumps is provided with an individual servo-motor acting directlyupon the piston of said pump to disconnect said piston from itsactuating mechanism.

3 Claims, 5 Drawing Figures Hummus 1:915 3750 s40 SHEET 1 BF 4 EMERGENCYSTOPPING DEVICE FOR A FUEL-INJECTION INTERNAL COMBUSTION ENGINE Thepresent invention relates to and has essentially for its object anemergency stopping device for an internal combustion engine of thefuel-injection type, for instance a Diesel engine.

In the known devices, in case of engine overspeed caused by an abruptdisappearance of the resisting moment, the tripping means, for instanceof the centrifugal type, slowing down or stopping the engine opens apressurized-fluid intake valve of the engine. The said fluid supplied toa single actuator, the piston of which acts collectively andsimultaneously upon all the actuating toothed racks of the injectionpumps, so as to stop the injection of fuel from all the pumps. However,when a casual jamming of the toothed rack or the mechanical transmissionbetween the actuator and the rack occurs, such a safety device can nolonger work. This leads to serious difficulties such as overspeed andracing" which may severely damage the engine.

The present invention has essentially for its purpose to avoid thedifficulties just mentioned, by providing for each pump a mechanicallyindependent emergency stopping of the discharge of the said pump,without acting upon its actuating member, for instance its toothed rack.

To this end, the emergency stopping device according to the invention ischaracterized in that each of the said pumps is provided with anindividual servo-motor acting directly upon the piston of the said pumpso as to disconnect its actuating member.

According to another feature of the present invention, each saidservo-motor comprises an actuator supplied with pressurized fluid by thesaid tripping means and mounted on the corresponding injection pump, anda lever connected,'on the one hand, to the piston of the said pump and,on the other hand, to the piston of the said actuator and pivotallymounted between its two ends at a fixed point of the said actuatorand/or the body of the said pump.

The invention will be better understood and other objects,characteristics and advantages thereof will appear as the followingdescription proceeds, with reference to the appended drawings givensolely by way of example illustrating several forms of embodiment of theinvention and wherein:

FIG. 1 is an emergency stopping system according to the invention, usedin connection with four fuelinjection pumps;

FIG. 2 is a vertical sectional view of an individual emergency stoppingdevice mounted on a fuel-injection pump;

FIG. 3 shows the device partially in vertical section upon the lineIIIIII of FIG. 2 (left side of the device), and partially in verticalsection (right side of the device) with a partially broken away view ofthe servomotor;

FIG. 4 is a longitudinal sectional view upon the line IV--IV of FIG. 2;

FIG. 5 is a partial longitudinal sectional view upon the line V-V ofFIG. 2.

The appended drawings and more particularly FIG. 1 diagrammaticallyillustrate a system of automatic regulation of the injection pumps 1 bymeans of a regulator 50 acting simultaneously upon the toothed racks 7of the pumps through the medium ofa linkage comprising a cranked shaft51 connected with the regulator by a resilient connecting member 52which, in case of need, enables the engine to be stopped by manuallyactuating the toothed racks by means of the crank 8. The safety deviceaccording to the invention is adapted to stop four fuel-injection pumpsin case of overspeed or racing of an internal combustion engine, forinstance a Diesel engine. During the operation of the engine undernormal working conditions, the outlet conduit 6" of theoverspeed-controlled tripping means 5 is connected with the conduit 6through which the oil is supplied to the four actuators 2. Thepressurized oil in the conduit 6' is thus discharged through the outletconduit 6". Under overspeed conditions, the centrifugal-acting trippingmeans 5, which is sensible to overspeed, operates as follows: thepush-rod 3 overcomes the action of the spring 3' and causes the lever 4to pivot by overcoming the action of the return spring 4'.

The slide valve 5' is then pushed to the right (in FIG. 1) by the returnspring 5", so that the pressurized-fluid intake valve 50 is opened andthe two conduits 6 and 6 are interconnected. The pressurized fluid, suchas for instance compressed air or pressurized oil, arrives through theconduit 6 in the direction indicated by the arrow in FIG. 1, flowsthrough the conduit 6 and is supplied to the four pneumatic or hydraulicactuators 2 which act upon the pistons of the respective fuelinjectionpumps 1, thus stopping the supply of fuel in the associated pumps 1,independently of the toothed rack 7 and according to a process whichwill be described later.

When the fuel supply is to be resumed, the draw-slide 5b is pulledmanually to reset the tripping means 5. The lever 4 returns to itsinitial position (shown in FIG. 1) under the action of the spring 4, thespring 3' returns the rod 3, and the conduits 6' and 6" are againinterconnected.

It is readily understood that owing to this principle, even if thetoothed rack 7 is casually jammed, the injection of fuel is stopped inthe pumps 1 by a direct and individual action upon each actuator 2regardless of the positions of the racks. The details concerning theemergency stopping device controlling the pistons of the fuel-injectionpumps 1 and the operating principle of the said device will be describedwith reference to FIGS. 2, 3, 4 and 5.

FIG. 2 shows a pneumatic or hydraulic actuator 2 mounted on a pump shownpartially and indicated generally by the reference digit 1. The actuator2 is a pneumatic or hydraulic actuator of a type known per se,comprising a piston 11, a piston rod 12, a seal 13 and a cylinder 14.The actuator 2 is mounted on a lateral orifice 15 permitting the access,for instance, to the system of regulation of the injection stroke of thepump 1. The pump 1 is a fuel-injection pump of a conventional type and,consequently, only the novel and advantageous elements provided by theinvention will be considered in the following description, withoutdescribing the mounting details already known in the art. At thejunction of the pump 1 and the pneumatic or hydraulic actuator 2, at thelevel of the orifice 15, is mounted a lever 16 provided with two forks18, 19 and adapted to pivot on its fulcrum 17. The end of the fork 18 ofthe pivotable lever 16 is located between the tappet 29 and the guide 20of the piston (not shown) of the pump 1. The lever 16 is retained in itscentral portion by a yoke 22 solid with the cylinder 14 (see FIGS. 3 and4).

Moreover, a lever 21 provided on the actuator 2 permits manualactuation, through the medium of the stopping device, of the piston ofthe associated injection pump 1 in order to prime the latter. The lever21 is pivotallymounted on a pin 25 of the link 24 hinged at 25 to themember 23 engaging the upper portion of the cylinder 14 of pneumatic orhydraulic actuator 2. The lever 21 also acts as an emergency handcontrol lever which permits manual actuation of the piston 11 of theactuator 2 in order to cut off the connection between the piston of thepump 1 and its actuating mechanism, in case of a failure of the trippingmeans 5.

Although the pneumatic or hydraulic actuator 2 is shown as beingadvantageously mounted on the pump 1 at the level of the opening 15, itis readily understood that it may be mounted at another point onthepump, the arrangement being so designed as to enable the fork 18 ofthe pivotable lever 16 to come into contact with the portion -26 (FIG.2) of the guide of the piston 20 of the pump 1, so as to raise thelatter as will be described herein under. In order to illustrate theforegoing general description of the mechanical elements of theemergency stopping device, the operation of the latter in case of engineoverspeed will now be explained.

As explained with reference to FIG. 1, in case of overspeed thecentrifugal-action tripping means controls all the actuators 2. Thiscontrol consists in opening the pressurized-fluid intake valve 5a, thesaid fluid being thus supplied to the hydraulic actuators 2 associated,respe'ctively,,with the pumps 1, by being conveyed by each conduit 27(FIG. 2) into the associated actuator. In each actuator the pressurizedfluid pushes the piston of the actuator 11 downwardly until the latter,occupies the position shown in dotted lines in FIG. 2. In movingvertically downward the piston 11 acts upon the pivotable lever 16through the medium of the fork 19. More specifically, the left arm (inFIG. 2) of the lever 16 is lowered to a lower position (shown in dottedlines in FIG. 2), whereas the right arm of the lever and, therefore, thefork 18 of the lever 16 is raised,

prising the tappet 29 and a cam (not shown). Thus, th supply of fuel iscompletely stopped.

The assembly formed by the lever 21 and its supporting elements 24, 25,25 is a removable assembly which is adapted, by a lateral or transversemotion, onto the cylinder head of each actuator 2, where it is retainedby being keyed under the flange of a projecting portion 14a integralwith the cylinder head. Thus, a single such assembly can be usedsuccessively for all the actuators 2.

The invention is applicable more particularly to the internal combustionengines of automotive vehicles and ships.

Of course, the invention is by no means limited to the forms ofembodiment described and illustrated, which have been given by way ofexample only. In particular, it comprises all the means constitutingtechnical equivalents to the means described as well as theircombinations, should the latter be carried out according to the spiritof the invention.

What is claimed is:

1. In an internal combustion engine of the fuelinjection type fed withfuel by injection pumps, each of which comprises a piston operated by anactuating mechanism releasably connected thereto, an emergency stoppingarrangement comprising tripping means adapted to supply servo-motorswith pressure fluid in case of overspeed of the engine, each of saidservemotors being associated with one of said-pumps and comprising apiston-type actuator mounted on the associated injection pump, and alever connected, on the one hand, to the piston of said pump and, on theother hand, to the piston of said actuator and pivotally mounted betweenits two ends on a stationary fulcrum point.

2. An arrangement according to claim 1, wherein each pump is formed witha lateral orifice giving access at least to the operative connectionbetween its piston and associated actuating mechanism and each one ofsaid actuators is mounted on said lateral orifice for releasablyengaging said connection.

3. An arrangement according to claim 1, wherein each one of saidactuators comprises a manual control lever for operating same.

1 a: :r a

1. In an internal combustion engine of the fuel-injection type fed withfuel by injection pumps, each of which comprises a piston operated by anactuating mechanism releasably connected thereto, an emergency stoppingarrangement comprising tripping means adapted to supply servo-motorswith pressure fluid in case of overspeed of the engine, each of saidserve-motors being associated with one of said pumps and comprising apiston-type actuator mounted on the associated injection pump, and alever connected, on the one hand, to the piston of said pump and, on theother hand, to the piston of said actuator and pivotally mounted betweenits two ends on a stationary fulcrum point.
 2. An arrangement accordingto claim 1, wherein each pump is formed with a lateral orifice givingaccess at least to the operative connection between its piston andassociated actuating mechanism and each one of said actuators is mountedon said lateral orifice for releasably engaging said connection.
 3. Anarrangement according to claim 1, wherein each one of said actuatorscomprises a manual control lever for operating same.